1. Field of the Invention
The present invention relates to a recording medium built-in cartridge including a recording medium built in a case. The present invention further relates to a cartridge built-in package including a recording medium built-in cartridge and a housing case capable of housing the recording medium built-in cartridge in an enclosed space.
2. Description of Related Art
Humidity is one of the major factors for degrading the properties of recording media such as magnetic tapes, magnetic disks and IC memory. If a recording medium built-in cartridge including these recording media built in a case is kept for a long time in humid surroundings, the recording media may erode or bacteria may propagate themselves. In recent years, ordinary housing has been improved in the air tightness, thus causing condensation easily. Recording medium built-in cartridges for general consumers are used and kept in such surroundings. Recording medium built-in cartridges for companies such as banks are required to have more excellent long-term storage capabilities than those required for products aimed at general consumers, so that they need to be kept in the surroundings where the humidity and the like are controlled. In practice, however, they rarely are kept in ideal surroundings.
In such a background, moisture exclusion devices for recording medium built-in cartridges or the like are disclosed. For instance, JP H07(1995)-242275 A discloses a moisture exclusion device provided with a desiccant such as silica gel housed in a case and a moisture permeable film provided at an opening of the case. This moisture exclusion device has approximately the same shape as that of a recording medium built-in cartridge (e.g., videotape cassette), and is kept in a housing rack together with recording medium built-in cartridges, thereby excluding the moisture from the recording medium built-in cartridges.
However, when the inside of the recording medium built-in cartridge is dried excessively, the characteristics of the recording medium are affected adversely. For example, in the instance of a tape cartridge including a case and a magnetic tape (recording medium) disposed in the case, a lubricant included in the magnetic tape may evaporate, thus degrading the magnetic tape.
Therefore, with the foregoing in mind, it is an object of the present invention to provide a recording medium built-in cartridge capable of keeping the humidity in a case within a predetermined range. Further, it is another object of the present invention to provide a cartridge built-in package including a recording medium built-in cartridge and a housing case capable of housing the recording medium built-in cartridge in an enclosed state, the cartridge built-in package capable of keeping the humidity in the case of the recording medium built-in cartridge within a predetermined range.